Wormholes are one of the significant predictions of the gravitational theories, which is still not confirmed observationally. In classical general relativity the construction of traversable wormholes is problematic since it requires the violation of the null energy condition. However, in quantum gravity this issue would be solved since quantum fields can provide in a natural way the necessary negative energy density. Alternatively, traversable wormholes arise in some modified theories of gravity like in the Gauss-Bonnet theory or \(f(R)\)  theories, where the energy conditions are violated by the gravitational interaction itself without the need of additional matter fields [1]}-[2]}. They can also exist in a mixed system with another compact object like a boson or neutron star [3]}-[4]}. Thus, the idea that traversable wormholes can form in nature is reasonably well supported by theoretical arguments, and one of the goals of the next generation gravitational experiments is to search for evidence for their existence.
